摘要:

Expressions are derived for the angles of departure of the root-loci from the open-loop system poles of linear multivariable systems and the angles of approach to the finite zeros of such systems. The concept of the finite zeros attractivity is introduced and its relation to the behaviour of the loci at intermediate gain values is discussed. The angles of approach of the loci that tend to the finite zeros ore also related to the angles of departure of the corresponding loci from the poles of the inverse system.

ISSN:0020-7179    

DOI:10.1080/00207177608922172

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

In this paper we study the effect of the sampling strategy on the achievable accuracy in linear system identification experiments. We consider the experiment as being composed of a number of subexperiments and we impose the constraint that the sampling rate should be constant in each of the subexperiments. We investigate the effect of having different sampling rates in each of the subexperiments and we show that the optimal information return can be achieved by use of a finite number of sub-experiments. We develop the theory in two parts : the first relating to the identification of a stochastic process from output observations ; the second relating to the identification of an input-output transfer function from noisy observations. We present a number of examples which show that the appropriate choice of sampling strategy can be of paramount importance in identification experiments. We also show that the design can be extended in a straightforward manner to safeguard against a single non-informative experiment in the case of diffuse prior distribution for the parameters.

ISSN:0020-7179    

DOI:10.1080/00207177608922173

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

In this paper a method is developed whereby the statistical characteristics of the response of non-linear stochastic systems are calculated with good accuracy. The method consists of the formulation and solution of the differential equations for the statistical characteristics of the processes under consideration. The development is based on the theory of Markov processes. In particular, use is made of Ito's differential rule to obtain a basic result which is used for the formulation of the differential equations. For the solution of the differential equations the method employs an approximate analytic representation of the probability density function of a random process. The representation is in the form of a finite Edgeworth (asymptotic) expansion. The method is quite general and yields accurate results. The treatment is illustrated by examples.

ISSN:0020-7179    

DOI:10.1080/00207177608922174

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

A procedure for designing a constant gain feedback matrix which assigns the closed-loop poles of a linear time-invariant multivariable system to desired locations and at the same time minimizes the sensitivity of these poles to variations in the parameters of the plant is described in this paper. It is shown that this technique in which sensitivity considerations are an integral part of the design procedure yields better results compared to other pole assignment techniques using constant gain feedback controllers. Numerical examples are presented to illustrate the application of the design procedure.

ISSN:0020-7179    

DOI:10.1080/00207177608922175

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

A method is presented for computing the characteristic polynomial and transfer function matrix corresponding to a phase-canonical form state-space description of a system. The proposed method leads to significant reduction in the computational effort over known techniques.

ISSN:0020-7179    

DOI:10.1080/00207177608922176

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

Many conventional design techniques can be only applied to ideal controlled objects without parameter variations and disturbances. This paper proposes a new method by which these techniques can be applied to practical objects with parameter variations and disturbances. The principle is to construct a model-following system which makes the practical object output follow the model output and to convert the practical object to the ideal object which has extremely low parameter and disturbance sensitivity.

ISSN:0020-7179    

DOI:10.1080/00207177608922177

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

The purpose of this paper is to study fixed-point smoothing problems from the viewpoint of the information theory. For a linear stochastic system it is proved that the necessary and sufficient condition for maximizing the mutual information between a state and the smoothed estimate is to minimize the entropy of the smoothed estimation error. Based on this relation between the mutual information and the error entropy, the optimal fixed-point smoothing estimator for a discrete-time linear system is derived. Furthermore, a similar estimator for a continuous-time linear system is also considered by an analogous approach.

ISSN:0020-7179    

DOI:10.1080/00207177608922178

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

A systematic method of designing stable decoupled systems using output feedback and a non-singular transformation on the output is outlined. These results are easily obtained by dualizing those on state variable feedback decoupling.

ISSN:0020-7179    

DOI:10.1080/00207177608922179

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

A predator-prey system is modelled by a pair of ordinary differential equations. Conditions are given under which enrichment of the system by increasing the prey carrying capacity leads to instability. More specifically, it is shown that there is a transition from a stable equilibrium point to oscillations and a stable limit cycle.

ISSN:0020-7179    

DOI:10.1080/00207177608922180

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor

摘要:

A predator-prey system is modelled by a pair of ordinary differential equations, and the qualitative effects of prey nutrient enrichment and predator harvesting on the stability of the system are studied. Some theoretical analysis concerning the existence of equilibrium points and limit cycles is included. Three models are examined as examples and the concept ofpractical stabilityis introduced. For one of the models, computer simulations are included to illustrate the changes in qualitative behaviour under nutrient enrichment and harvesting. The results indicate that care must be taken in harvesting to prevent extinction of the predator and a resulting collapse of the entire ecosystem. This study should, therefore, prove to be a useful tool in resource management and control.

ISSN:0020-7179    

DOI:10.1080/00207177608922181

出版商:Taylor & Francis Group    

年代:1976

数据来源: Taylor